////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2011-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <QAction>
#include <QMainWindow>
#include <QMenu>
#include <QMenuBar>

#include "Figure.h"
#include "Menu.h"
#include "QtHandlesUtils.h"

#include "octave-qobject.h"

namespace octave
{

  static QKeySequence
  accelSequence (const uimenu::properties& up)
  {
    std::string s (up.get_accelerator ());

    if (! s.empty ())
      {
        char c = s[0];
        int keyMod = Qt::CTRL;

        if (c >= 'A' && c <= 'Z')
          keyMod |= Qt::SHIFT;
        if (c >= 'a' && c <= 'z')
          c -= ('a' - 'A');
        if (c >= 'A' && c <= 'Z')
          return QKeySequence (keyMod | static_cast<int> (c));
      }

    return QKeySequence ();
  }

  Menu*
  Menu::create (octave::base_qobject& oct_qobj, octave::interpreter& interp,
                const graphics_object& go)
  {
    Object *parent_obj = parentObject (interp, go);

    if (parent_obj)
      {
        QObject *qObj = parent_obj->qObject ();

        if (qObj)
          return new Menu (oct_qobj, interp, go, new QAction (qObj),
                           parent_obj);
      }

    return nullptr;
  }

  Menu::Menu (octave::base_qobject& oct_qobj, octave::interpreter& interp,
              const graphics_object& go, QAction *action, Object *xparent)
    : Object (oct_qobj, interp, go, action), m_parent (nullptr),
      m_separator (nullptr)
  {
    uimenu::properties& up = properties<uimenu> ();

    action->setText (Utils::fromStdString (up.get_text ()));

    if (up.is_checked ())
      {
        action->setCheckable (true);
        action->setChecked (up.is_checked ());
      }

    action->setEnabled (up.is_enable ());
    action->setShortcut (accelSequence (up));
    action->setVisible (up.is_visible ());

    if (up.is_separator ())
      {
        m_separator = new QAction (action);
        m_separator->setSeparator (true);
        m_separator->setVisible (up.is_visible ());
      }

    MenuContainer *menuContainer = dynamic_cast<MenuContainer *> (xparent);

    if (menuContainer)
      m_parent = menuContainer->menu ();

    if (m_parent)
      {
        int pos = static_cast<int> (up.get_position ());

        if (pos <= 0)
          {
            if (m_separator)
              m_parent->insertAction (nullptr, m_separator);
            m_parent->insertAction (nullptr, action);

            int count = 0;

            for (auto *a : m_parent->actions ())
              if (! a->isSeparator ())
                count++;

            up.get_property ("position").set
            (octave_value (static_cast<double> (count)), true, false);
          }
        else
          {

            int count = 0;
            QAction *before = nullptr;

            for (auto *a : m_parent->actions ())
              {
                if (! a->isSeparator ())
                  {
                    count++;
                    if (pos <= count)
                      {
                        before = a;
                        break;
                      }
                  }
              }

            if (m_separator)
              m_parent->insertAction (before, m_separator);
            m_parent->insertAction (before, action);

            if (before)
              updateSiblingPositions ();
            else
              up.get_property ("position").set
              (octave_value (static_cast<double> (count+1)), true, false);
          }
      }

    connect (action, &QAction::triggered, this, &Menu::actionTriggered);
  }

  Menu::~Menu (void)
  { }

  void
  Menu::update (int pId)
  {
    uimenu::properties& up = properties<uimenu> ();
    QAction *action = qWidget<QAction> ();

    switch (pId)
      {
      case uimenu::properties::ID_TEXT:
        action->setText (Utils::fromStdString (up.get_text ()));
        break;

      case uimenu::properties::ID_CHECKED:
        if (up.is_checked ())
          {
            action->setCheckable (true);
            action->setChecked (up.is_checked ());
          }
        else
          {
            action->setChecked (false);
            action->setCheckable (false);
          }
        break;

      case uimenu::properties::ID_ENABLE:
        action->setEnabled (up.is_enable ());
        break;

      case uimenu::properties::ID_ACCELERATOR:
        if (! action->menu ())
          action->setShortcut (accelSequence (up));
        break;

      case uimenu::properties::ID_SEPARATOR:
        if (up.is_separator ())
          {
            if (! m_separator)
              {
                m_separator = new QAction (action);
                m_separator->setSeparator (true);
                m_separator->setVisible (up.is_visible ());
                if (m_parent)
                  m_parent->insertAction (action, m_separator);
              }
          }
        else
          {
            if (m_separator)
              delete m_separator;
            m_separator = nullptr;
          }
        break;

      case uimenu::properties::ID_VISIBLE:
        action->setVisible (up.is_visible ());
        if (m_separator)
          m_separator->setVisible (up.is_visible ());
        break;

      case uimenu::properties::ID_POSITION:
        {
          if (m_separator)
            m_parent->removeAction (m_separator);

          m_parent->removeAction (action);

          int pos = static_cast<int> (up.get_position ());
          QAction *before = nullptr;

          if (pos > 0)
            {
              int count = 0;

              for (auto *a : m_parent->actions ())
                {
                  if (! a->isSeparator ())
                    {
                      count++;
                      if (pos <= count)
                        {
                          before = a;
                          break;
                        }
                    }
                }
            }

          if (m_separator)
            m_parent->insertAction (before, m_separator);

          m_parent->insertAction (before, action);

          updateSiblingPositions ();
        }
        break;

      default:
        Object::update (pId);
        break;
      }
  }

  QWidget*
  Menu::menu (void)
  {
    QAction *action = qWidget<QAction> ();
    QMenu *action_menu = action->menu ();

    if (! action_menu)
      {
        action_menu = new QMenu (action->parentWidget ());
        action->setMenu (action_menu);
        action->setShortcut (QKeySequence ());
        connect (action_menu, &QMenu::aboutToShow, this, &Menu::actionHovered);
      }

    return action_menu;
  }

  void
  Menu::actionTriggered (void)
  {
    QAction *action = qWidget<QAction> ();

    if (action->isCheckable ())
      action->setChecked (! action->isChecked ());
    emit gh_callback_event (m_handle, "callback");
  }

  void
  Menu::actionHovered (void)
  {
    emit gh_callback_event (m_handle, "callback");
  }

  void
  Menu::updateSiblingPositions (void)
  {
    if (m_parent)
      {
        double count = 1.0;

        for (auto *a : m_parent->actions ())
          {
            if (! a->isSeparator ())
              {
                Object *aObj = Object::fromQObject (a);

                if (aObj)
                  {
                    graphics_object go = aObj->object ();

                    // Probably overkill as a uimenu child can only be another
                    // uimenu object.
                    if (go.isa ("uimenu"))
                      {
                        uimenu::properties& up = Utils::properties<uimenu> (go);

                        up.get_property ("position").set
                        (octave_value (count), true, false);
                      }
                  }

                count++;
              }
          }
      }
  }

}
